The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 18, 1982
Filed:
Jan. 03, 1980
Tokyo Shibaura Denki Kabushiki Kaisha, Kawasaki, JP;
Abstract
In an optical apparatus for inspecting optical defects, a laser beam generated from a laser unit is converted by a collimator lens into a light beam having a suitable diameter. An X-Y scanner for two-dimensionally scanning the light beam is situated at a forward focal point of a scanning lens. The light beam passed through the scanning lens is converged substantially in parallel with an optical axis of the scanning lens and is reflected by a semi-transparent mirror and is vertically projected onto a flat surface to be inspected of an article situated substantially at a backward focal point of the scanning lens. Thus, on the surface to be inspected of the article there is given a projected beam spot having a larger diameter than that of the relevant circle of least confusion. The light rays reflected by the article surface to be inspected are converged by a converging lens the forward focal point of which is located on the said article surface. The light rays regularly reflected by that article surface are converged by the converging lens to a spatial filter and one cut off by the same. Only light rays irregularly reflected by the article surface enters a photo-detecting unit through the spatial filter.